1. Field of Invention
This invention relates to a semiconductor process, and more particularly relates to a high-density-plasma CVD (HDP-CVD) process, to a filling-in process utilizing HDP-CVD, and to an HDP-CVD system applicable to the HDP-CVD process.
2. Description of Related Art
As the linewidth of integrated circuit (IC) fabricating process is much reduced, the HDP-CVD technique is widely used in depositions of various materials, especially insulating materials, due to its gap-filling capability. An HDP-CVD process has both a deposition effect and an etching effect, wherein the etching effect is largest at the gap corners so that the material is well filled in the gaps.
Moreover, to improve the quality of the deposited film, a wafer is usually pre-heated in-situ in the HDP-CVD chamber before the deposition is started. However, since plasma is generated in the pre-heating step in the HDP-CVD chamber, the wafer surface is easily damaged by the ion bombardment from the plasma.